In an existing Long Term Evolution (LTE for short) wireless communications network, to determine radio signal quality at a location of user equipment (UE for short), the UE needs to perform reference signal measurement on a cell that serves the UE or a cell on which the UE camps, and in consideration of mobility of the UE, the UE also needs to perform measurement on a neighboring cell. These measurement values include a reference signal received power (RSRP for short), reference signal received quality (RSRQ for short), and the like. The RSRP and the RSRQ are relatively important measurement values among all measurement values. As an RSRP of a cell measured by the UE increases, strength of a signal received by the UE from the cell increases. As RSRQ of a cell measured by the UE increases, quality of a signal received by the UE from the cell increases. As the UE moves in a direction away from a cell A, an RSRP of the cell A that is measured and that is fed back by the UE gradually decreases. As the UE moves in a direction towards a cell B, an RSRP of the cell B that is measured and that is fed back by the UE gradually increases. That is, when the UE is moving, RRM measurement values are continuously measured and fed back. A base station then finds, by using the corresponding RRM measurement values, whether a cell that provides a service to the UE needs to be changed, or the like.
The UE generally performs data transmission in two manners. Manner 1: The UE performs data transmission by means of a single cell service. Manner 2: The UE performs data transmission by means of a multimedia broadcast multicast service (MBMS for short). In Manner 2, multiple cells send data to at least one UE by using a data transmission method of a single frequency network (SFN for short). Further, an LTE system is geographically divided into multiple cells, and a corresponding base station provides a service to each cell. An MBMS service is generally performed according to an MBMS area. Specifically, several cells (which are generally neighboring cells) in a network may form one MBMS area, and cells that belong to one area all send a broadcast multicast service that belongs to this area. For example, if a television program of CCTV1 is provided in one area, all cells in this area provide this program. Moreover, all cells in this area simultaneously send a signal of this program on a same time-frequency resource. In this way, strength of a transmitted signal of the MBMS can be increased, and particularly, received strength of a cell edge user is increased.
When UE moves between two base stations that belong to different MBMS areas or moves between a base station that belongs to an MBMS area and a base station that belongs to a non-MBMS area, to determine whether to perform a cell handover, in the prior art, the UE measures radio signal quality of a source base station and a target base station, and it is determined, based on obtained measurement values of radio signal quality, for example, an RSRP and RSRQ above, whether to perform a cell handover. However, when a manner of measuring radio signal quality of a source base station and a target base station in the prior art is used to determine whether to perform a cell handover, a premature handover is usually caused, which results in an unnecessary handover procedure, or a handover is performed too late, which results in a service interruption.